JPH03278519A - Chemical detection mechanism of chemical applicator - Google Patents

Abstract

PURPOSE:To enable sensing the defective discharge of chemicals, i.e., defective application thereof and as a result to obtain a detection mechanism, which can reduce a product fraction defective in a semiconductor device, by having an optical detector for detecting the discharge rate of chemicals directly under the chemical discharge nozzle of a chemical application part. CONSTITUTION:Directly under the chemical discharge nozzle 2 of the application part 3 of a chemical applicator for applying chemicals 1 to a semiconductor substrate 4, an apparatus has optical detectors 5, 6 for detecting the discharge rate of the chemicals 1. For example, optical detector light-emitting part 5 and light-receiving part 6 for chemicals detection with the chemicals 1 discharged from the chemical nozzle 2 between are installed directly under the chemical nozzle 2, respective two types are provided for both light-emitting part 5 and light-receiving part 6 so that laser light 7 can be applied from the light-emitting part 5 with the space of width L, and the width L is a diameter at the time of regarding the chemicals 1 discharged normally from the chemical nozzle 2 as a cylinder. Further, the light of the detector is shielded when the discharge operation of chemicals is performed normally. Therefore, it is confirmed by the use of electric information that light-shielding of the detector is performed for the expected chemical discharge period.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an improvement in a chemical coating device, and more particularly to a mechanism for detecting the amount of a chemical discharged when the chemical coating device discharges a chemical to a semiconductor substrate.

[Conventional technology]

Conventionally, the chemical liquid detection mechanism of this type of chemical liquid applicator has been used for indirect detection, that is, to check the operation of the chemical liquid pump that is the chemical liquid discharging means, for example, whether the bellows type pump has moved a certain certain stroke within the chemical liquid discharging time. Methods such as confirmation were used.

By the way, it is extremely difficult to use the above-mentioned method when the means for pressure-feeding the chemical liquid is a diaphragm pump or a rotary pump, and when it comes to pressurizing the chemical liquid using a gas such as nitrogen, it is difficult to achieve a quantitative discharge amount. Detection is completely impossible.

[Problem to be solved by the invention]

The chemical liquid detection mechanism of the conventional chemical liquid coating device described above does not directly detect the chemical liquid discharged onto the semiconductor substrate, so even if a large amount of air bubbles are mixed into the chemical liquid and the chemical liquid is insufficiently discharged, There is no way to know this, and there are disadvantages in that it causes a coating failure on the semiconductor substrate and the detection is delayed.

The following four main causes of air bubbles being mixed into the chemical solution are listed below.

(1) When the chemical solution contains an organic solvent, the solvent vaporizes and foams under negative pressure caused by the suction action of the pump.

(2) Cracks in the chemical piping system and loose fittings.

(3) Air contamination during filter replacement, etc. in cases where a chemical solution filtration means is provided.

(4) Malfunction of chemical liquid detection mechanism, empty detection 1! ! If it does not contain air, air will be mixed in when the chemical solution is emptied.

SUMMARY OF THE INVENTION An object of the present invention is to provide a chemical liquid detection mechanism for a chemical liquid applicator that can detect a chemical discharge failure, that is, a coating failure, and as a result can significantly reduce the product defect rate in semiconductor devices. .

[Means to solve the problem]

The chemical liquid detection mechanism of the chemical liquid coating apparatus of the present invention has an optical detector installed directly below the chemical liquid discharge nozzle of the chemical liquid coating processing section of the chemical liquid coating apparatus that applies a chemical liquid to a semiconductor substrate.

〔Example〕

Next, the present invention will be explained with reference to the drawings. FIG. 1 is a side view showing an embodiment of the present invention. Discharge of the chemical solution is performed by the same device as in the past, using a chemical solution pressure feeding means such as a pump (not shown).

The chemical solution 1 is discharged from the chemical solution nozzle 2 onto the semiconductor substrate 4 in the coating processing section 3 .

Immediately below the chemical liquid nozzle, an optical detector light emitting part 5 and an optical detector light receiving part 6 for detecting the chemical liquid are installed, sandwiching the chemical liquid discharged from the chemical liquid nozzle.

Next, a method for detecting a chemical solution will be described with reference to FIG. 2, which is a plan view of FIG. 1. The optical detector has two sets of light emitting parts and light receiving parts, and can emit, for example, laser light 7 at wide intervals from the light emitting parts. The width is the diameter when the chemical liquid normally discharged from the chemical liquid nozzle is not regarded as a cylinder. In addition,
1 is the diameter of the chemical liquid nozzle.

Under the above conditions, first, the optical detector is made to emit light, and then the chemical liquid is ejected from the chemical liquid nozzle. If the ejection operation is performed normally, the light from the detector is blocked. At this time, the detector can confirm that the dispensing operation of the chemical solution has started normally, but an electrical signal is also used to confirm that the detector has been shielded from light for the intended dispensing time T. If you check the discharge amount of the chemical solution at the point of use, you can monitor it.

In the above situation, if the discharge amount of the chemical solution is small, that is, L
If is smaller than the expected value, the fact that the detector was not shielded from light within the chemical liquid ejection time T can be considered as a defect.

FIG. 3 is a plan view showing a second embodiment of the invention. Unlike the first embodiment, the optical detector 5 is of a type that detects and outputs the width of the light-shielded portion, that is, the diameter of the chemical directly below the chemical nozzle in the figure. As in the case of the first embodiment, the amount of chemical liquid discharged is confirmed when an electric signal corresponding to the width is output from the detector during the expected chemical liquid discharge time T.

The detector in this case is of a type that can detect the diameter of the medicinal solution if the object to be detected, that is, the medicinal solution, is in the region of the light beam of the detector shown in FIG.

In the first embodiment, if there is a positional deviation of the chemical liquid due to a slight positional deviation of the chemical liquid nozzle, the positional relationship between the blocking and receiving of the detection light shifts, resulting in false detection.
This embodiment has the advantage that the above-mentioned problem does not occur as long as the chemical solution is in the region of the light beam of the detector. By monitoring the amount of chemical liquid discharged onto the substrate, defective discharge of the chemical liquid, that is, defective coating of the chemical liquid can be immediately detected, which has the effect of significantly reducing the product defect rate in semiconductor manufacturing.

[Brief explanation of drawings]

FIG. 1 is a side view showing one embodiment of the present invention, and FIG. 2 is a side view showing one embodiment of the present invention.
FIG. 3 is a plan view showing a second embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Chemical liquid, 2... Chemical liquid nozzle, 3... Coating processing part, 4... Semiconductor substrate, 5... Optical detector light emitting part, 6... Optical detector light receiving part.

Claims (1)

[Claims] A chemical liquid detection mechanism for a chemical liquid coating apparatus, comprising an optical detector for detecting a discharge amount of the chemical liquid directly below a chemical liquid detection nozzle of a coating processing section of the chemical liquid coating apparatus that applies a chemical liquid to a semiconductor substrate.